Shell script to remove unassigned simple products

cleanup.php

<?php
/**
 * This script is used to clean up unassigned simple products
 *
 * @author      Alexander Turiak <[email protected]>
 * @copyright   Copyright (c) 2014 HexBrain (http://www.hexbrain.com)
 */

require_once 'abstract.php';

class CleanUp extends Mage_Shell_Abstract
{
    public function run()
    {
        $dryRun = $this->getArg('dry-run');

        // Get all the simple product ids
        $allSimples = Mage::getResourceModel('catalog/product_collection')
            ->addAttributeToFilter('type_id', array('eq' => Mage_Catalog_Model_Product_Type::TYPE_SIMPLE))
            ->getAllIds();

        $resource = Mage::getSingleton('core/resource');
        $readConnection = $resource->getConnection('core_read');

        // Get all the assigned product ids
        $select = $readConnection->select()
            ->from($resource->getTableName('catalog/product_super_link'), array('product_id'))
            ->where('product_id IN (?)', $allSimples);

        $allAssigned = $readConnection->fetchCol($select);

        // All unassigned products
        $allUnAssigned = array_diff($allSimples, $allAssigned);

        if (count($allUnAssigned) == 0) {
            echo 'Nothing to do here: no unassigned products to remove' . PHP_EOL;
            return;
        }

        if ($dryRun == 'no') {
            echo 'This will actually remove products. WARNING: There is no rollback' . PHP_EOL . PHP_EOL;
        }

        $product = Mage::getModel('catalog/product');
        foreach ($allUnAssigned as $productId) {
            $product->load($productId);
            if ($dryRun == 'no') {
                echo 'Removing unassigned product ' . $product->getSku() . PHP_EOL;
                $product->delete();
            } else {
                echo 'Product ' . $product->getSku() . ' will be removed' . PHP_EOL;
            }
        }

        if ($dryRun == 'no') {
            echo PHP_EOL . 'Done.' . PHP_EOL;
        } else {
            echo PHP_EOL . $this->usageHelp();
        }

    }

    public function usageHelp()
    {
        return <<<USAGE
Usage:  php -f cleanup.php -- [options]

  --dry-run     Dry run, doesn't actually delete products (default mode)
                Pass "no" as value to bypass
USAGE;
    }

}

$cleanup = new CleanUp();
$cleanup->run();